Mesostructured film, mesoporous material film, and production methods for the same

ABSTRACT

A mesostructured film is provided having a structure in which surfactant molecular assemblies are regularly arranged three-dimensionally. A polymer compound thin film is formed on the substrate surface through spin coating or the like, and a rotating roller wrapped with a cloth is pressed against the polymer film for rubbing in one direction. The polymer material includes polyimide, polyamide, and polystyrene. The substrate includes a silica glass substrate and a silicon substrate. The mesostructured film can be formed by retaining the substrate in an aqueous solution containing a surfactant, silicon alkoxide, and acid. After being retained in the solution, the substrate is heated at about 60 to 120° C. for several hours to several days for reaction. The surfactant includes C 18 H 37 (OCH 2 CH 2 ) 20 OH and C 16 H 33  (OCH 2 CH 2 ) 20 OH. The alkoxide included tetraethoxysilane, tetramethoxysilane, and tetrapropoxysilane. Hydrochloric acid, nitric acid, or sulfuric acid is used as a catalyst.

TECHNICAL FIELD

The present invention relates to a film having a novel nanometer-scaleperiodic structure, and more specifically to a structure, amesostructured film, and a mesoporous material film each having aregular periodic structure formed through self-assembly and productionmethods for the same.

BACKGROUND ART

There are several reports on the preparation of a mesostructured filmand a mesoporous material film each having a three-dimensional regularperiodic structure. The preparation of silica mesostructured filmshaving a cubic structure or a three-dimensional hexagonal structurethrough dip-coating using various surfactants has been reported inAdvanced Materials, vol. 10, p. 1380 (1998). Further, an example inwhich using a double-headed ammonium surfactant containing twoquaternary nitrogens bonded through a methylene group, a mesoporoussilica film having a three-dimensional hexagonal structure is formed ona mica substrate through deposition has been reported in Chemistry ofMaterials, vol. 9, p. 1962.

Meanwhile, there are several reports on a technique of controlling amesopore alignment of a mesostructured material at a macroscopic scale.A method using a polymer film subjected to rubbing treatment is reportedin Chemistry of Materials, vol. 11, p. 1609.

However, in the above-described reports, there are some points to beimproved.

First, a mesostructured film prepared through the solvent evaporationsuch as dip-coating has locally a three-dimensional regular structure onthe substrate, but it is hard to highly control the regular structureacross an entire substrate. In most cases, the structure is isotropic orslightly anisotropic to in-plane rotation when the structure of theentire substrate is averaged out. Further, in a technique of forming amesostructured film having a three-dimensional regular structure throughdeposition on a substrate retained in a precursor solution, control ofmesopore arrangement across the entire substrate has not been confirmedat a macroscopic scale. Further, a usable substrate is limited to mica,and a very special surfactant is needed.

Further, in a conventional technique of controlling orientation ofmesopores in mesostructure silica at a macroscopic scale, the targetstructure is limited to a tubular pore structure of a two-dimensionalhexagonal structure.

DISCLOSURE OF THE INVENTION

The present invention has been made in view of the above, and provides amesostructured film having a structure of surfactant molecularassemblies regularly arranged three-dimensionally, which has anarrangement of the molecular assemblies highly controlled across anentire substrate, is arranged on an optional substrate using generalsurfactants and is applied to a novel X-ray optical device.

That is, the present invention provides a mesostructured film includingamphiphilic molecular assemblies and a compound containing as a maincomponent an inorganic material formed on the peripheries of themolecular assemblies regularly arranged three-dimensionally, themesostructured film being formed on a substrate, in which: a localperiodic structure in an optional section of the film in parallel withthe substrate has a 6-fold axis perpendicular to the film plane; andsymmetric reflective surfaces of the structure including the 6-fold axisare facing in the same direction across the entire film.

The present invention provides a mesoporous material film includingholes regularly arranged three-dimensionally and an inorganic materialas a main component, the mesoporous material film being formed on asubstrate, in which: a local periodic structure in an optional sectionof the film in parallel with the substrate has a 6-fold axisperpendicular to the film plane; and symmetric reflective surfaces ofthe structure including the 6-fold axis are facing in the same directionacross the entire film.

Further, the present invention provides a structure including sphericalassemblies of amphiphilic molecules and a compound containing aninorganic material formed on the peripheries of the assemblies, inwhich: the amphiphilic molecular assemblies are, regularly arrangedacross the entire area of the structure; and the arrangement of theamphiphilic molecular assemblies has a 6-fold axis.

Still further, the present invention provides a production method for amesostructured film including the steps of: preparing a substrate havingan anisotropic surface; preparing a reactant solution containing two ormore kinds of surfactants and an inorganic material precursor; andretaining the substrate having an anisotropic surface in the reactantsolution.

The present invention provides a production method for a structureincluding assemblies of amphiphilic molecules and a compound containingan inorganic material formed on the peripheries of the assemblies, theproduction method for a structure including the steps of: preparing asubstrate having an anisotropic surface and a solution containing aninorganic compound and having a molar concentration at which theamphiphilic molecules form spherical micelles; and retaining thesubstrate in the solution, thereby forming the structure on thesubstrate.

A substrate having an anisotropic surface is preferably used in thepresent invention.

A substrate having a polymer compound formed thereon and subjected torubbing treatment is particularly preferably used in the-presentinvention. Polyimide is preferable as the polymer compound.

As described above, according to the present invention, a mesostructuredfilm having a three-dimensional regular structure, in which a localstructure in an optional section in parallel with a substrate surfacehas a 6-fold axis perpendicular to the film plane and in-planeorientation of an arrangement is identical across the entire substrate,can be created by forming a mesostructured film on the substrate havingan anisotropic surface using appropriate surfactants under suitableconditions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a mesostructured film and themesoporous material film prepared in the present invention, in which alocal periodic structure in an optional section of the film in parallelwith the substrate has a 6-fold axis perpendicular to the film plane andsymmetric reflective surfaces of the structure including the 6-fold axisare facing in the same direction across the entire film;

FIG. 2 is a schematic diagram showing a reaction vessel used inproduction of the mesostructured film in the present invention, in whicha local periodic structure in an optional section of film in parallelwith the substrate has a 6-fold axis perpendicular to the film plane andsymmetric reflective surfaces of the structure including the 6-fold axisare facing in the same direction across the entire film;

FIG. 3 is a schematic diagram showing a dip coating apparatus for themesostructured film in the present invention, in which a local periodicstructure in an optional section of the film in parallel with thesubstrate has a 6-fold axis perpendicular to the film plane andsymmetric reflective surfaces of the structure including the 6-fold axisare facing in the same direction across the entire film;

FIG. 4 shows θ-2θ scanning X-ray diffraction patterns measured for themesostructured film produced in Example 1 of the present invention;

FIG. 5 shows diffraction patterns illustrating anisotropy of in-planeX-ray diffraction patterns measured for the mesostructured film producedin Example 1 of the present invention;

FIG. 6 shows an in-plane rocking curve of a lattice plane correspondingto a peak having greater intensity among the in-plane X-ray diffractionpeaks measured for the mesostructured film produced in Example 1 of thepresent invention;

FIG. 7 is a diagram showing a structure of an X-ray optical device usingthe present invention;

FIG. 8 is a schematic diagram showing apparatus for preparing aLangmuir-Blodgett film of polyimide in Example 2 of the presentinvention;

FIG. 9 shows θ-2θ scanning X-ray diffraction patterns measured for themesostructured film produced in Example 3 of the present invention;

FIG. 10 shows in-plane diffraction patterns measured for themesostructured film produced in Example 3 of the present invention;

FIG. 11 shows an in-plane rocking curve of a lattice plane correspondingto a peak having greater intensity among the in-plane X-ray diffractionpeaks measured for the mesostructured film produced in Example 3 of thepresent invention; and

FIG. 12 is a schematic diagram illustrating a pattern of themesostructured film produced in Example 8 of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a schematic diagram showing the structure of themesostructured film and mesoporous material film of the presentinvention in an optional section in parallel with a substrate surface.In the present invention, the mesostructured film and mesoporousmaterial film 12 formed on a substrate 11 includes a local periodicstructure in an optional section having a 6-fold axis “a” perpendicularto the film plane. Further, identical symmetric reflective surfaces A ofthe structure including the 6-fold axis “a” are facing in the samedirection across the entire film at a centimeter scale or more. That is,A and A′ planes are parallel anywhere in the substrate in FIG. 1. InFIG. 1, amphiphilic molecular assemblies or pores 13 exposed at theoutermost surface are represented by circles for simple explanation.However, actually, spherical or nearly spherical amphiphilic molecularassemblies or pores are typically arranged in closest packingthree-dimensionally, thereby forming a three-dimensional regularstructure. However, a structure of the mesostructured film andmesoporous material film in the present invention is not limitedthereto, and any structure having regularity related to the abovesymmetry can also be applied.

A mesostructured film in the present invention is a composite structurefilm composed of amphiphilic molecular assemblies and a compoundcontaining as a main component an inorganic material formed on theperipheries of the molecular assemblies regularly arrangedthree-dimensionally. That is, a film containing surfactants is referredto as the mesostructured film. Further, the film of hollow structuresformed through removal of the surfactants from the film is referred toas the mesoporous material film. The term “meso” as used hereincorresponds to a size of 2 nm or more and 50 nm or less, and to adiameter of a section of an amphiphilic molecular assembly or mesopore,when the section of the film is assumed to be circular.

Hereinafter, production methods for the mesostructured film andmesoporous material film in the present invention will be described.

First, a production method for the target mesostructured film in thepresent invention will be described. Various reports on the productionmethod for the mesostructured film may be roughly classified into twomethods including: a method called solvent evaporation; and a methodbased on heterogeneous nucleation and growth on a substrate. Themesostructured film in the present invention may be produced througheither method as long as direction control of amphiphilic molecularassemblies or pores as described above can be attained on the substrate.

The method based on heterogeneous nucleation and growth issatisfactorily used for the present invention. The production methodwill be described below.

First, a production method for a substrate will be described.

In the present invention, use of a substrate having a polymer film withan anisotropic surface formed thereon will be described. However, thesubstrate having an anisotropic surface applicable to the presentinvention is not limited thereto, and a crystalline substrate having ananisotropic surface such as the (110) plane of silicon can be used aslong as the target structure can be produced. In such a case, it is amatter of course that a step of forming a polymer thin film describedbelow is not required. A polymer thin film with an anisotropic surfacecan be produced through a method such as rubbing treatment or aLangmuir-Blodgett method. However, the method of forming a polymer withan anisotropic surface used in the present invention is not limited tothe above two methods, and any methods inducing anisotropy can beapplied. Anisotropy may be imparted through polarized irradiation, forexample.

First, the rubbing treatment will be described. A thin film of a polymeris formed on a substrate surface through a method such as spin-coatingor dip-coating, and a rotating roller wrapped with a cloth is pressedagainst the thin film for rubbing in one direction. A polymer materialused is not particularly limited inasmuch as the material withstands theproduction process of a mesostructured film described below. Examples ofthe polymer material that can be used include polyimide, polyamide, andpolystyrene. For example, a polyimide thin film can be formed by:applying polyamic acid, which is a precursor, on a substrate; and thensubjecting the substrate to heat treatment. Any material can be used forthe substrate on which a polymer film is formed as long as the materialwithstands the production process of a mesostructured film describedbelow. Examples of the substrate that can be satisfactorily appliedinclude a silica glass substrate and a silicon substrate. A thickness ofa polymer thin film is not particularly limited, and is preferably inthe range of several nano meters to several hundreds nano meters. Amaterial for the cloth wrapped Around a rubbing roller is notparticularly limited, and examples thereof include cotton and nylon.Anisotropy imparted through the rubbing treatment varies depending onthe structure of the polymer used. It is considered that there are acase where anisotropy may be imparted mainly to only shape and a casewhere anisotropy is imparted to shape and polymer structure. In thepresent invention, both the cases are usable as long as the alignment ofthe mesopores formed on the polymer thin film can be controlledaccordingly.

Next, the Langmuir-Blodgett method will be described. TheLangmuir-Blodgett method is formed by transferring a monomolecular layerconsisting of an amphiphilic material formed at a gas-liquid interfaceonto a substrate, and can be formed as a film of a desired number oflayers by repeating this film formation. The “Langmuir-Blodgett film” asused herein refers to not only a film formed at a gas-liquid interfaceand transferred onto the substrate, but also a film transferred onto thesubstrate and then subjected to treatment for modification. ALangmuir-Blodgett film can also be formed from a polymer compound.

For example, a method of forming a Langmuir-Blodgett film of polyimidewill be described. An alkylamine salt of polyamic acid, which is aprecursor of the target polyimide, is synthesized. The salt is dissolvedin an appropriate solvent, and is added dropwise onto a water surface.Thus, a monomolecular film of polyamic acid can be formed on the watersurface. A Langmuir-Blodgett film of polyamic acid having a desiredthickness is formed by immersing and extracting the substrate into andfrom the water. After film formation, the film is subjected to heattreatment in a nitrogen atmosphere for dehydration imidation anddeamidation, thereby forming a Langmuir-Blodgett film of polyimide. Aninfrared absorption spectroscopy or the like of the Langmuir-Blodgettfilm of polyimide confirmed that polymer chains are oriented in atransfer direction of the substrate during film formation.

Next, a mesostructured film is formed on a substrate having ananisotropic polymer surface thereon produced as described above.Hereinafter, the present invention will be described regarding amesostructured silica film produced through a method based onheterogeneous nucleation and growth on a substrate, but the presentinvention is not limited thereto.

The mesostructured silica film can be formed by retaining the substratein an aqueous solution containing a surfactant which is an amphiphilicmolecule, silicon alkoxide which is a silica source, and an acid servingas a hydrolysis catalyst. On the substrate, surfactant micelles whichare amphiphilic molecular assemblies and an alkoxide precursor which isproduced through hydrolysis and is a silica precursor form amesostructured silica film regularly arranged through self-assembly.

FIG. 2 is a schematic diagram showing a reaction vessel used for filmformation. A material for a reaction vessel 21 is not particularlylimited as long as the material is inert and does not participate inreaction. An example of the material preferably used includes Teflon(trademark). A substrate 25 is retained in a solution and then placed ina heating device at about 60 to 120° C., if required, for reaction forseveral hours to several days. The reaction vessel is provided with acover 22 and sealed with an O-ring 24 or the like for preventingdestruction of the vessel or leak from the 20 vessel during heating. Thereaction vessel of FIG. 2 may be placed in a stronger vessel ofstainless steel or the like.

A nonionic surfactant containing ethylene oxide as a hydrophilic groupis preferably used as a surfactant, and examples thereof includeC₁₉H₃₇(OCH₂CH₂)₂₀OH, and C₁₆H₃₃(OCH₂CH₂)₂₀OH. A mixture of two or moresurfactants can also be used. The two or more surfactants havepreferably common identical hydrophobic structure and hydrophilicpolyethylene oxide with different molecular length from each other.Examples of the mixtures that can be used include: a mixture ofC₁₆H₃₃(OCH₂CH₂)₂OH and C₁₆H₃₃ (OCH₂CH₂)₁₀OH; and a mixture ofC₁₈H₃₇(OCH₂CH₂)₂₀OH and C₁₈H₃₇ (OCH₂CH₂)₁₀OH. However, the surfactantand the mixtures of the two or more surfactants that can be used are notlimited to the above, and any mixtures may be used as long as the targetstructure can be provided.

Examples of alkoxide that can be satisfactorily used as a silica sourceinclude tetraethoxysilane, tetramethoxysilane, and tetrapropoxysilane.

Hydrochloric acid, nitric acid, sulfuric acid, or the like is used as anacid serving as a hydrolysis catalyst, but hydrochloric acid is mostgenerally used.

Concentrations of a surfactant, an acid, and a silica source greatlyaffect a mesostructure to be formed. Inappropriate conditions may resultin a discontinuous film or a mesostructure not having the targetthree-dimensional regular structure. A mesostructured film is formedunder the conditions optimized for a surfactant to be used throughevaluation on the structure, morphology, or the like of the final film.

X-ray diffraction analysis is generally used for structural evaluationof a film. θ-2θ scanning is used for investigating a periodic structurein parallel with a substrate, and rocking curve measurement of in-planeX-ray diffraction analysis is used for investigating symmetry on thefilm plane. Cross-sectional transmission electron microscopy can also beeffectively used.

Optical microscopes and scanning electron microscopes are used formorphological observation of a film. Observation of scanning electronmicroscopes is preferably carried out under low acceleration voltagewithout metal deposition.

If required, surfactants are removed from the mesostructured silica filmproduced as described above, thereby forming a mesoporous silica film.The removal of the surfactant increases a difference in electron densitybetween silica walls and the inside of the mesopores. Thus, X-rayscattering intensity tends to increase, but at the same time themesostructure may be distorted, lowering regularity.

Any methods among the various methods of removing the surfactant can beused as long as the method allows removal of the surfactant withoutdestruction of a pore structure.

A method most generally used involves calcining in an atmospherecontaining oxygen. For example, calcination of a mesostructured silicafilm in air at 550° C. for 10 hours results in complete removal of anorganic component while the pore structure is retained. A polymer filmformed on a substrate surface is also removed in this case, and thus,the final structure includes a mesoporous silica film directly formed onthe substrate.

A method of removing the surfactant through extraction with a solvent orusing a supercritical fluid is known as a method of removing thesurfactant in addition to the calcination. When using such a method, itis hard to remove an organic component completely, but it makes itpossible to form a mesoporous silica film on a substrate of a materialnot withstanding high temperatures during calcination.

Further, ozone oxidation is also possible as a method of removing thesurfactant in addition to calcination and extraction. The method alsoallows removal of the surfactant at temperatures lower than that incalcination.

The film of the present invention may contain the surfactant in pores ormay not contain the surfactant through removal of the surfactant as longas the film has the target structure. Further, the film may contain amaterial in the pores except the surfactant.

When the mesostructured film and mesoporous film of the presentinvention are evaluated through in-plane X-ray diffraction, sixdiffraction peaks are observed every 60° within the range of 360° in arocking curve profile of in-plane periodic structure.

The result indicates that the film of the present invention has a 6-foldaxis perpendicular to a film plane. Further, in the in-plane X-raydiffraction analysis, an incident angle is close to a total reflectioncritical angle and is very small. Thus, adjusting a sample to beanalyzed to an appropriate size provides averaged information across theentire sample film. The measurement of the film of the present inventionunder the conditions allowing measurement of the entire film resulted inthe above-described diffraction peaks. This indicates that latticeplanes providing the diffraction peaks of 6-fold rotational symmetry arein the identical direction across the entire film.

Further, when two or more kinds of surfactants are mixed to be used, thefull width of the half maximum of the diffraction of the rocking curveprofile observed in the in-plane X-ray diffraction analysis becomesignificantly small. This indicates that the distribution of in-planepore orientation is narrow and structural controllability has beenimproved.

In addition to the above method based on heterogeneous nucleation andgrowth on the substrate, a method based on the sol-gel method issatisfactorily used. Such a production method will be described below.The production method involves: coating the substrate with a precursorsolution containing surfactants, a silica precursor, water, and an acidas a hydrolysis catalyst, or setting the solution at an optionalposition on the substrate; and carrying out reaction such as solventdrying, condensation and the like. Examples of satisfactory solvent forthe precursor solution used in the method include alcohols such asethanol and isopropanol, but are not limited thereto.

The precursor solution having such a composition is applied onto thesubstrate or set at an optional position on the substrate. Variouscoating methods such as dip-coating, spin-coating, and mist-coating canbe used. Other methods can be used inasmuch as they allow uniformcoating. A device used for spin-coating or dip-coating can be generalone and is not particularly limited. The device may be provided withcontroller of temperature of the solution and temperature and humidityof an atmosphere in which the coating is carried out.

A production method for a mesostructured film using dip-coating will bedescribed as an example.

FIG. 3 is a schematic diagram showing an example of a device used fordip-coating. In FIG. 3, reference numerals 31, 32, and 33 represent avessel, a substrate, and a precursor solution, respectively.

A substrate on which a mesostructured thin film is formed is fixed to arod 35 using a substrate holder 34 and moved upward and downward with az stage 36.

During film formation, the precursor solution 33 is controlled todesired temperature, if required, a heater 38 and a thermocouple 37. Forimproving the controllability of the solution temperature, the entirevessel may be placed in an insulated container (not shown). A thicknessof the thin film can be controlled by changing the coating conditions.

Further, various methods such as microcontact printing method, inkjetmethod, and pen lithography method can be used as a method of applyingthe precursor solution at an optional position onto the substrate. Suchmethods allow patterning of a mesostructured thin film at a desiredposition on the substrate.

Soft lithography is a technique for pattern formation involving:pressing an elastic mold (micromold) made from a material such aspolydimethylsiloxane onto the substrate; introducing the precursorsolution from the edge of the mold by capillarity; polymerizing amaterial forming pore walls to form a mesostructure; and then removingthe mold to produce a pattern. The method allows very easy patterning ofa mesostructure if the structure is simple.

Pen lithography involves: using a precursor solution as ink; andapplying the solution from a tip of a pen to draw lines. A pen shape, atransfer rate of the pen or a substrate, a fluid supply rate to the pen,or the like may be varied to change line widths freely. Lines withwidths of μm order to mm order can be drawn at present. Optionalpatterns such as straight lines and curved lines can be drawn, and sheetpatterning is possible by overlapping spreads of the reactant solutionapplied on the substrate.

Further, an inkjet method is effective for drawing a pattern ofdiscontinuous dots. The method involves: using reactant solution as ink;and discharging a constant amount of the solution as droplets from aninkjet nozzle for coating. Further, linear patterning and sheetpatterning are possible by carrying out coating so that spreads of thereactant solution applied on the substrate overlaps. An emission amountof one droplet can be controlled to be several pico liters in the inkjetmethod at present. Thus, very minute dots can be formed, and the methodis advantageous in patterning of minute dot shapes.

Further, according to those coating methods such as pen lithography andink jet method desired patterns can be easily determined by using acomputer system such as CAD. Thus, the coating methods differ from usualpatterning by photolithography involving changing masks, and are veryadvantageous in production efficiency when various patterns are formedon various substrates.

The film of the present invention has such a feature that a structuralperiod of the film is longer by one digit or more as compared to astructural period of a crystal, and shows stronger diffraction with softX-rays of a longer wavelength region as compared to X-rays causingdiffraction of crystals. Thus, the film of the present invention can beapplied to an optical film using a long periodic structure and using thediffraction with X-rays of long wavelengths at large angles.

As described above, the gist of the present invention is characterizedby controlling a three-dimensional structure of a material havingnano-scale spacings at a macroscopic scale at high levels through asimple method based on self-assembly; and applying the structuralregularity thus controlled to X-ray optical materials.

Hereinafter, the present invention will be described in more detail byway of Examples, but the present invention is not limited to theExamples.

EXAMPLE 1

Example 1 is an example in which using a substrate having a polyimidefilm formed thereon and subjected to rubbing treatment, a mesostructuredsilica film is formed on the substrate to produce an optical materialthin film in soft X-ray region. The mesostructured silica film has astructure with a 6-fold axis perpendicular to the film plane and hassymmetric reflective surfaces of the structure including the 6-fold axisin the same direction across the entire film. FIG. 1 schematicallyillustrates the structure of the film produced in Example 1.

An NMP solution of polyamic acid A was applied through spin-coating ontoa silica glass substrate washed with acetone, isopropyl alcohol, andpure water and having a surface cleaned in an ozone generatingapparatus. The substrate was then calcined at 200° C. for 1 hour, tothereby form polyimide A having the following structure.

Rubbing treatment was carried out under the conditions shown in Table 1,thereby forming a substrate.

TABLE 1 Cloth material Nylon Roller 24 diameter (mm) Pressing (mm) 0.4Rotation (rpm) 1,000 Stage rate 600 (mm/min) Number of 2 repeats

A mesostructured silica film was formed on this substrate. A surfactantused in Example 1 was a nonionic surfactant polyethylene oxide 20octadecyl ether (C₁₈H₃₇(CH₂CH₂O)₂OH, abbreviated as C₁₈EO₂₀ below)having polyethylene oxide as a hydrophilic group.

0.92 g of C₁₈EO₂₀ was dissolved in 129 ml of pure water, and 20.6 ml ofconcentrated hydrochloric acid (36%) was added thereto. After sufficientstirring of the mixture, 2.20 ml of tetraethoxysilane (TEOS) was furtheradded to the solution, and was stirred for 3 minutes. The final molarratio of respective components in the solution was TEOS:H₂O:HCl:C₁₈EO₂₀=0.125:100:3:0.01.

The substrate having polyimide A formed thereon and subjected to rubbingtreatment was retained in the reactant solution with the side on whichthe film was to be formed facing down. A Teflon (trademark) vessel 21 ofthe constitution as shown in FIG. 2 containing the reactant solution wassealed for reaction at 80° C. for 3 days. A cover was placed on thesurface through a spacer during reaction, thereby obtaining asatisfactory uniaxially oriented mesostructured silica film.

A substrate 25 held in contact with the reactant solution for a giventime was taken out from the vessel, sufficiently washed with pure water,and naturally dried at room temperature. As a result, a continuous filmof the mesostructured silica was formed on the substrate. The thicknessof the mesostructured silica film was determined using a stylusprofilometer, and was about 200 nm.

The film was subjected to θ-2θ) scanning X-ray diffraction analysis withCuKα radiation, and two sharp diffraction peaks corresponding to planeinterval of 5.96 nm and 3.00 nm respectively, were observed as shown inFIG. 4. No difference appeared in diffraction patterns between a casewhere the measurement was carried out in the direction of a substrateplane projection component of incident X-rays parallel with the rubbingdirection and a case where the measurement was carried out in thedirection of a substrate plane projection component of incident X-raysperpendicular to the rubbing direction.

The structure of the film was more specifically analyzed throughin-plane X-ray diffraction analysis with CuKα radiation. The measurementmethod is described in Chemistry of Materials, vol. 11, p. 1609, forexample, and provides information regarding lattice planes nothorizontal with the substrate, which cannot be observed by θ-2θscanning.

The in-plane X-ray diffraction analysis showed diffraction peaks atplane interval of 7.64 nm and 3.79 nm as shown in FIG. 5. Theintensities of the diffraction peaks were small with measurement in suchan initial arrangement that the substrate plane projection component ofthe incident X-rays was parallel with the rubbing direction. Theintensities were large with measurement in such an initial arrangementthat the substrate plane projection component of the incident X-rays wasperpendicular to the rubbing direction, thereby confirming strongin-plane anisotropy in the orientation of the lattice plane.

Next, a detector was fixed at positions of plane interval of 7.46 nm and3.79 nm in the in-plane X-ray diffraction analysis and the sample wassubjected to in-plane rotation, to investigate the orientation of theplane. As a result, diffraction peaks were observed every 60° at equalintervals as shown in FIG. 6. Positions of diffraction peaks were indirections of +150°, +90°, +30°, −30°, −90°, and −150° with respect tothe rubbing direction.

The above results showed that the mesostructured film produced in thepresent invention has a structure with a 6-fold axis perpendicular tothe film plane. An incident angle of X-rays was 0.2° in the in-planeX-ray diffraction analysis. The entire sample corresponds to theanalysis region, and thus, in-plane orientation is identical across theentire substrate. In other words, symmetric reflective surfaces of thestructure each including the 6-fold axis are facing in the samedirection across the entire film.

Next, the film was calcined in air to remove the surfactant. The filmwas heated to 550° C. at a temperature increase rate of 2° C./min,maintained at the temperature for 10 hours, and then cooled to roomtemperature. Infrared absorption spectroscopy or the like showed that noorganic components remained in the calcined film.

The calcined film was analyzed by X-ray diffraction, and the diffractionpeaks similar to those in FIG. 4 were observed, thereby confirming thatthe structure was retained even after removal of the surfactant.However, positions of the diffraction peaks shifted to higher angles ascompared to peak positions in FIG. 4, indicating that a structuralperiod perpendicular to the film plane shortened through calcination.This results from shrinkage of a structure through dehydrationcondensation of a silanol group of silica constituting pore walls.

Further, the calcined sample film was analyzed through in-plane X-raydiffraction, and the diffraction patterns substantially identical tothose in FIG. 5 were obtained. The result showed that the shrinkage ofthe structure occurs only in a direction perpendicular to the substratesurface and that the in-plane periodic structure does not change throughcalcination.

In-plane rocking curve was measured for the calcined sample by fixing adetector at positions of the in-plane diffraction peaks and rotating thesample. A pattern substantially identical to that in FIG. 6 wasobserved, indicating that in-plane structural regularity was slightlychanged by removal of the surfactant through calcination.

An example in which the mesoporous silica film produced as describedabove is used as an X-ray optical device will be described below.

X-rays were incident on the mesoporous silica film produced in Example1, arranged shown in FIG. 7. The X-rays used were soft X-rays ofwavelength 13 nm. The soft X-rays are absorbed by air. Thus, X-raysource, a sample holder holding the mesoporous silica film, and adetection surface of a detector are provided in vacuum. An incidentangle a is set to be an angle substantially identical to the totalreflection critical angle of the sample for the arrangement inExample 1. Incident X-rays AO to the sample with the arrangement almosttotally reflect at an interface, reflection (OB) at an angle identicalto the incident angle on the sample surface.

A structural period in the in-plane direction of the film produced inExample 1 was 7.89 nm, and a diffraction angle was 55.5° with CuKαradiation. Thus, with a suitable sample direction, the diffracted X-rays(OC) are emitted at this angle.

In the present invention, a sample holder is provided with atwo-direction tilt angle adjustment stage, Z stage for a heightadjustment, and φ stage for in-plane rotation of the sample. Thus, theincident angle can be adjusted to an optimum value.

Intensity of light diffraction has correlation with incident X-rays whenan optical system of such structure is used. Thus, incident X-rayintensity can be determined while using X-ray beam for analysis or thelike by monitoring the diffraction peaks.

Further, by rotating the substrate at a constant rate, the intensitiesof the diffraction peaks are unevenly emphasized.

As described above, the film of Example 1 can be applied to a novelX-ray optical device.

COMPARATIVE EXAMPLE 1

A mesostructured silica film was produced using a silica glass substratewashed with acetone, ethanol, and pure water and having the surfacecleaned with ozone, and following the procedure shown in Example 1. Atransparent continuous mesostructured silica film was formed on thesubstrate in this step.

The film was analyzed through θ-2θ scanning X-ray diffraction with CuKαradiation, and diffraction peaks substantially identical to those inFIG. 4 were observed. Diffraction patterns substantially identical tothose in FIG. 5 observed in Example 1 were also obtained throughin-plane X-ray diffraction analysis. The results showed that amesostructured silica film can be formed directly on the silica glass inComparative Example 1.

In-plane rocking curve measurement was also carried out for the filmproduced in Comparative Example 1 by fixing a detector to the in-planediffraction peaks. However, no periodic intensity change as in Example 1was observed, indicating that the structure formed was random in theplane.

That is, the results indicated that structures having similar symmetryare formed locally when no anisotropy is imparted to the substrate, andthat the orientation cannot be identical across the entire substrate.

EXAMPLE 2

Example 2 is an example of production of: a Langmuir-Blodgett film ofpolyimide on a substrate; a mesoporous silica film having a structurewith a 6-fold axis perpendicular to the film plane and having symmetricreflective surfaces of the structure each including the 6-fold axis inthe same direction across the entire film; and an optical material thinfilm in soft X-ray region. FIG. 1 schematically shows the structure ofthe film prepared in Example 2.

Polyamic acid B and N,N-dimethylhexadecylamine were mixed in a molarratio of 1:2, to prepare an N,N-dimethylhexadecylamine salt of polyamicacid B. The salt was dissolved in N,N-dimethylacetamide to prepare a 0.5mM solution, and the resultant solution was added dropwise onto a watersurface of an LB film formation device maintained at 20° C. FIG. 8 showsa schematic diagram of the LB film formation device. A monomolecularfilm formed on the water surface was transferred onto the substrate at adip rate of 5.4 mm/min while the constant surface pressure of 30 mN/mwas applied. The substrate used was a silica glass substrate washed withacetone, isopropyl alcohol, and water and having a surface cleaned in anozone generating apparatus. After formation of a 30-layer LB film of analkylamine salt of polyamic acid on the substrate, the film was calcinedin stream of nitrogen gas at 300° C. for 30 minutes, thereby forming anLB film of polyimide B having the structure described below. An infraredabsorption spectroscopy indicated imidation through dehydration ringclosure of the polyamic acid and desorption of alkylamine.

A polarized infrared absorption spectroscopy indicated that thepolyimide thin film produced in Example 2 has a polymer chain orientedin parallel with a direction of the substrate pulled out during filmformation.

A mesostructured silica film was formed on the 5 substrate. A surfactantused in Example 2 was a nonionic surfactant polyethylene oxide 20 cetylether (C₁₆H₃₃(CH₂CH₂O)₂₀OH, abbreviated as C₁₆EO₂₀ below) havingpolyethylene oxide as a hydrophilic group.

0.90 g of C₁₆EO₂₀ was dissolved in 129 ml of pure water, and 20.6 ml ofconcentrated hydrochloric acid (36%) was added thereto. After sufficientstirring of the mixture, 2.20 ml of tetraethoxysilane (TEOS) was furtheradded to the solution, and was stirred for 3 minutes. The final molarratio of respective components in the solution wasTEOS:H₂O:HCl:C₁₆EO₂₀=0.125:100:3:0.0075.

The substrate having a Langmuir-Blodgett film of polyimide B formedthereon was retained in the reactant solution with the side on which thefilm was to be formed facing down. The Teflon (trademark) vessel 21 ofthe constitution as shown in FIG. 2, which is the same as that inExample 1, containing the reactant solution was sealed for reaction at80° Cl. for 3 days. A cover was placed on the surface through a spacerduring reaction, thereby obtaining a satisfactory uniaxially orientedmesostructured silica film.

The substrate 25 held in contact with the reactant solution for a giventime was taken out from the vessel, sufficiently washed with pure water,and naturally dried at room temperature. As a result, a continuous filmof a mesostructured silica was formed on the substrate. A thickness ofthe mesostructured silica film was determined using a stylusprofilometer, and was about 200 nm.

The film was subjected to θ-2θ scanning X-ray diffraction analysis withCuKα radiation, and two sharp diffraction peaks corresponding to planeintervals of 5.60 nm and 2.80 nm respectively, were observed as in FIG.4. No difference appeared in diffraction patterns between a case wherethe measurement was carried out in the direction of a substrate planeprojection component of incident X-rays parallel with the rubbingdirection and a case where the measurement was carried out in thedirection of a substrate plane projection component of incident X-raysperpendicular to the rubbing direction.

The structure of the film was more specifically analyzed throughin-plane X-ray diffraction analysis. The in-plane X-ray diffractionanalysis showed a diffraction peak at a plane interval of 7.35 nm, as inFIG. 5. Two diffraction peaks were observed in Example 1, but no cleardiffraction peak was observed at a position corresponding to half of theperiod in Example 2.

The intensities of the diffraction peaks were small with measurement insuch an initial arrangement that the substrate plane projectioncomponent of the incident X-rays was parallel with the rubbingdirection. The intensities were large with measurement in such aninitial arrangement that the substrate plane projection component of theincident X-rays was perpendicular to the rubbing direction, therebyconfirming strong in-plane anisotropy in orientation of the latticeplane even in the film produced in Example 2.

Next, a detector was fixed at a position of a plane interval of 7.35 nmin the in-plane X-ray diffraction analysis, and the sample was subjectedto in-plane rotation, investigating the orientation of the plane. As aresult, a substantially identical profile was obtained as in FIG. 6 anddiffraction peaks were observed every 60° at equal intervals. Positionsof the diffraction peaks were in directions of +150°, +90°, +30°, −30°,−90°, and −150° with respect to the rubbing direction.

The above results showed that the mesostructured film produced in thepresent invention has a structure with a 6-fold axis perpendicular tothe film plane. An incident angle of X-rays was 0.2° in the in-planeX-ray diffraction analysis. The entire sample corresponds to an analysisregion, and thus, in-plane orientation of the structure is identicalacross the entire substrate. In other words, symmetric reflectivesurfaces of the structure each including the 6-fold axis are facing inthe same direction across the entire film.

The mesostructured silica film produced in Example 2 was then calcinedunder the same conditions as those in Example 1 to remove thesurfactant, thereby forming a mesoporous silica film.

The calcined film was analyzed by X-ray diffraction, and the resultindicated that a structural period was shrank only in a thicknessdirection.

The film produced in Example 2 upon X-ray analysis exhibited similarbehavior to the film in Example 1, and thus, the film can be applied tothe optical device described in Example 1.

EXAMPLE 3

In Example 3, a substrate having a polyimide film formed thereon andsubjected to the same rubbing treatment as in Example 1 was produced. Amesostructured silica film was formed on the substrate. A surfactantused in Example 3 was a mixture of two kinds of surfactants respectivelyhaving hydrophilic polyethylene oxide portions different in size andhaving identical hydrophobic alkyl chains. The surfactant containedpolyethylene oxide 20 hexadecyl ether (C₁₆H₃₃(CH₂CH₂O)₂₀OH, abbreviatedas C₁₆EO₂₀ below) and polyethylene oxide 10 hexadecyl ether(C₁₆H₃₃(CH₂CH₂O)₁₀OH, abbreviated as C₁₆EO₁₀ below) mixed in a molarratio of C₁₆EO₁₀:C₁₆EO₂₀=2:1.

0.32 g of C₁₆EO₁₀ and 0.26 g of C₁₆EO₂₀ were dissolved in 129 ml of purewater, and 20.6 ml of concentrated hydrochloric acid (36%) was addedthereto. After sufficient stirring of the mixture, 2.20 ml oftetraethoxysilane (TEOS) was further added to the solution, and wasstirred for 3 minutes. The final molar ratio of respective components inthe solution was TEOS:H₂O:HCl:C₁₆EO₁₀:C₁₆EO₂₀=0.125:100:3:0.0059:0.0029.

The substrate having polyimide A formed thereon and subjected to rubbingtreatment was retained in the reactant solution with the side on whichthe film 20 was to be formed facing down; The Teflon (trademark) vessel21 of the constitution as shown in FIG. 2 containing the reactantsolution was sealed for reaction at 80° C. for 3 days. A cover wasplaced on the surface through a spacer during reaction, thereby 25obtaining a satisfactory uniaxially oriented mesostructured silica film.

The substrate 25 held in contact with the reactant solution for a giventime was taken out from the vessel, sufficiently washed with pure water,and naturally dried at room temperature. As a result, a continuous filmof a mesostructured silica was formed on the substrate. A thickness ofthe mesostructured silica film was determined using a stylusprofilometer, and was about 400 nm.

The film was subjected to θ-2θ scanning X-ray diffraction analysis withCuKα radiation, and diffraction peaks corresponding to plane intervalsof 5.3 nm and 2.7 nm were observed at 1.66° and 3.24°, respectively.Anisotropy was observed in the diffraction patterns between a case wherethe measurement was carried out in the direction of a substrate planeprojection component of incident X-rays parallel with the rubbingdirection (pattern a in FIG. 9) and a case where the measurement wascarried out in the direction of a substrate plane projection componentof incident X-rays perpendicular to the rubbing direction (pattern b inFIG. 9). That is, two diffraction peaks in addition to the above twodiffraction peaks were observed in the case where the measurement wascarried out in the rubbing direction of the sample perpendicular to theX-rays. Such anisotropy of the diffraction patterns indicates that thefilm has strong structural anisotropy.

The structure of the film was more specifically analyzed throughin-plane X-ray diffraction analysis with CuKα radiation as in Example 1.The in-plane X-ray diffraction analysis showed two diffraction peaks at2θ_(X)=1.18° and 2.36°, and the result shown in FIG. 10 which is similarto the result of Example 1 shown in FIG. 5 was observed, therebyconfirming strong in-plane anisotropy in orientation of the latticeplane.

Next, a detector was fixed at a position of 2θ_(X)=1.18° in the in-planeX-ray diffraction analysis, and the sample was subjected to in-planerotation, investigating the orientation of the plane. As a result, sharpdiffraction peaks were observed every 60° at equal intervals as shown inFIG. 11. The positions of the diffraction-peaks were in directions of+150°, +90°, +30°, −30°, −90°, and −150° with respect to the rubbingdirection. The full width of the half maximum of the diffraction in therocking curve of Example 3 in FIG. 11-observed through in-plane X-raydiffraction analysis are smaller than those of Example 1 in FIG. 6,indicating a narrow distribution of in-plane pore orientation andimproved structural controllability.

From the above results, it was confirmed that the structure of themesostructured film produced in Example 3 includes a 6-fold axisperpendicular to the film plane, and that the distribution of theorientation is very narrow. An incident angle of X-rays was 0.2° in thein-plane X-ray diffraction analysis. The-entire sample corresponds to ananalysis region, and thus, in-plane orientation of the structure isidentical across the entire substrate. In other words, symmetricreflective surfaces of the structure each including a 6-fold axis arefacing in the same direction across the entire film.

Next, the film was calcined in air to remove the surfactant. The filmwas heated to 550° C. at a temperature increase rate of 2° C./min,maintained at the temperature for 10 hours, and then cooled to roomtemperature. An infrared absorption spectroscopy or the like showed thatno organic components remained in the calcined film.

The calcined film was analyzed by X-ray diffraction, and diffractionpeaks as in FIG. 9 were observed, thereby confirming that the structurewas retained after removal of the surfactant. However, positions of thediffraction peaks shifted to higher angles as compared to peak positionsin FIG. 9, indicating that a structural period perpendicular to the filmplane was shortened by calcination. This results from shrinkage of thestructure through dehydration condensation of silanol groups of silicaconstituting pore walls.

Further, the calcined sample film was analyzed through in-plane X-raydiffraction, and diffraction patterns substantially identical to thosein FIG. 10 were obtained, whereby it was confirmed that the shrinkage ofthe structure occurs only in a direction perpendicular to the substratesurface and the in-plane periodic structure does not change throughcalcination.

In-plane rocking curve was measured for the calcined sample by fixing adetector at positions of the in-plane diffraction peaks and rotating thesample. A pattern substantially identical to that in FIG. 11 wasobserved, indicating that in-plane structural regularity was slightlychanged through removal of the surfactant by calcination.

The film produced in Example 3 upon X-ray analysis exhibited similarbehavior to the film in Example 1, and thus, the film can be applied tothe optical device described in Example 1.

EXAMPLE 4

In Example 4, a substrate having a Langmuir-Blodgett film formed thereonwas first produced as in Example 2.

A mesostructured silica film was formed on the substrate. A surfactantused in Example 4 was the same as used in Example 3: a mixture ofpolyethylene oxide 20 hexadecyl ether (C₁₆H₃₃(CH₂CH₂O)₂₀OH, abbreviatedas C₁₆EO₂₀ below) and polyethylene oxide 10 hexadecyl ether(C₁₆H₃₃(CH₂CH₂O)₁₀OH, abbreviated as C₁₆EO₁₀ below) mixed in a molarratio of C₁₆EO₁₀:C₁₆EO₂₀=2:1.

A composition of the reactant solution for mesostructured silica filmformation was the same as prepared in Example 3.

The substrate having a Langmuir-Blodgett film of polyimide B formedthereon was retained in the reactant solution with the side on which thefilm was to be formed facing down. The Teflon (trademark) vessel 21 ofthe constitution as shown in FIG. 2 containing the reactant solution,which is the same as in Example 1, was sealed for reaction at 80° C. for3 days. A cover was placed on the surface through a spacer duringreaction, thereby obtaining a satisfactory uniaxially orientedmesostructured silica film.

The substrate 25 held in contact with the reactant solution for a giventime was taken out from the vessel, sufficiently washed with pure water,and naturally dried at room temperature. As a result, a continuous filmof a mesostructured silica was formed. A thickness of the mesostructuredsilica film was determined using a stylus profilometer, and was about500 nm.

The film was analyzed by θ-2θ scanning X-ray diffraction with CuKαradiation, and two diffraction peaks corresponding to plane interval of5.3 nm and 2.7 nm similar to those in FIG. 9 were observed at positionsof 1.66° and 3.24°, respectively. Anisotropy in the diffraction patternsas in Example 3 was observed between a case where the measurement wascarried out in the direction of a substrate plane projection componentof incident X-rays parallel with the transfer direction of the substrateduring LB film formation and a case where the measurement was carriedout in the direction perpendicular to the transfer direction of thesubstrate during LB film formation.

The structure of the film was more specifically analyzed throughin-plane X-ray diffraction with CuKα radiation. As a result, twodiffraction peaks were observed at 2θ_(X)=1.18° and 2.36° as in Example3. The intensities of the diffraction peaks were small with measurementin such an initial arrangement that the substrate plane projectioncomponent of the incident X-rays was parallel with the transferdirection of the substrate during LB film formation. The intensitieswere large with measurement in such an initial arrangement that thesubstrate plane projection component of the incident X-rays wasperpendicular to the transfer direction of the substrate during LB filmformation, thereby confirming strong in-plane anisotropy in orientationof the lattice plane.

Next, a detector was fixed at a position of 2θ_(X)=1.18° in the in-planeX-ray diffraction analysis, and the sample was subjected to in-planerotation, investigating the orientation of the plane. As a result, asubstantially identical profile was obtained as in FIG. 11, anddiffraction peaks were observed every 60° at equal intervals. Thepositions of the diffraction peaks were in directions of +150°, +90°,+30°, −30°, −90°, and −150° with respect to the transfer direction ofthe substrate during LB film formation.

From the above results, it was confirmed that the structure of themesostructured film produced in the present invention includes a 6-foldaxis perpendicular to the film plane, and that the distribution of theorientation is very narrow. An incident angle of X-rays was 0.2° in thein-plane X-ray diffraction analysis. The entire sample corresponds to ananalysis region, and thus, in-plane orientation is identical across theentire substrate. In other words, symmetric reflective surfaces of thestructure each including a 6-fold axis are facing in the same directionacross the entire film.

The mesostructured silica film produced in Example 4 was then calcinedunder the same conditions as in Example 3 to remove the surfactant,thereby forming a mesoporous silica film.

The calcined film was analyzed by X-ray diffraction, and the resultindicated that a structural period was shortened only in a thicknessdirection.

The film produced in Example 4 upon X-ray analysis exhibited similarbehavior to the film in Example 1, and thus, the film can be applied toan optical device described in Example 1.

EXAMPLE 5

Example 5 is an example of production of a mesostructured silica andmesoporous silica film having a three-dimensional structure within-plane orientation highly controlled across the entire substrate as inExamples 3 and 4 by using: a substrate having a polyimide film formedthereon and subjected to the same rubbing treatment as in Example 1; anda different surfactant from that in Examples 3 and 4.

A polyimide A film was formed on a silica glass substrate in the samemanner as in Example 1, and the substrate was subjected to rubbingtreatment under the same conditions as in Example 1.

A mesostructured silica film was formed on the substrate. A surfactantused in Example 5 was also a mixture of two kinds of surfactantsrespectively having hydrophilic polyethylene oxide portions different insize and having identical hydrophobic alkyl chains which are differentin length from the alkyl chains of the surfactants used in Example 3.The surfactant used in Example 5 contained polyethylene oxide 20octadecyl ether (C₁₈H₃₇(CH₂CH₂O)₂₀OH, abbreviated as C₁₈EO₂₀ below) andpolyethylene oxide 10 octadecyl ether (C₁₈H₃₇(CH₂CH₂O)₁₀OH, abbreviatedas C₁₈EO₁₀ below) mixed in a molar ratio of C₁₈EO₁₀: C₁₆EO₂₀=1:3.

0.16 g of C₁₈EO₁₀ and 0.76 g of C₁₈EO₂₀ were dissolved in 129 ml of purewater, and 20.6 ml of concentrated-hydrochloric acid (36%) was addedthereto. After sufficient stirring of the mixture, 2.20 ml oftetraethoxysilane (TEOS) was further added to the solution, and wasstirred for 3 minutes. The final molar ratio of respective components inthe solution was TEOS:H₂O:HCl:C₁₈EO₁₀:C₁₈EO₂₀=0.125:100:3:0.0028:0.0083.

The substrate having polyimide A formed thereon and subjected to rubbingtreatment was retained in the reactant solution with the side on whichthe film was to be formed facing down. The Teflon (trademark) vessel 21containing the reactant solution, which is the same as in Examples 3 and4, was sealed for reaction at 80° C. for 3 days. A cover was placed onthe surface through a spacer during reaction, thereby obtaining asatisfactory uniaxially oriented mesostructured silica film.

The substrate 25 held in contact with the reactant solution for a giventime was taken out from the vessel, sufficiently washed with pure water,and naturally dried at room temperature. As a result, a continuous filmof a mesostructured silica was formed. The thickness of themesostructured silica film was determined using a stylus profilometer,and was about 400 nm.

The film was analyzed by θ-2θ scanning X-ray diffraction with CuKαradiation, and diffraction peaks corresponding to plane interval of 6.0nm and 3.0 nm were observed at 1.47° and 2.95°, respectively. Anisotropyin the diffraction patterns as in Example 3 was observed between a casewhere the measurement was carried out in the direction of a substrateplane projection component of incident X-rays parallel with the rubbingdirection and a case where the measurement was carried out in thedirection of a substrate plane projection component of incident X-raysperpendicular to the rubbing direction.

The structure of the film was more specifically analyzed throughin-plane X-ray diffraction with CuKα radiation. Two diffraction peakswere observed at 2θ_(X)=1.12° and 2.20° through in-plane X-raydiffraction analysis. As in Example 3, the intensities of thediffraction peaks were small with measurement in such an initialarrangement that the substrate plane projection component of theincident X-rays was in parallel with the rubbing direction. Theintensities were large with measurement in such an initial arrangementthat the substrate plane projection component of the incident X-rays wasperpendicular to the rubbing direction, thereby confirming stronganisotropy in an in-plane structure of the mesostructured silicaproduced in Example 5.

Next, a detector was fixed at a position of 2θ_(X)=1.12° in the in-planeX-ray diffraction analysis, and the sample was subjected to in-planerotation, investigating the orientation of the plane. As a result, sharpdiffraction peaks were observed every 60° at equal intervals as inExample 3. The positions of the diffraction peaks were in directions of+150°, +90°, +30°, −30°, −90°, and 150° with respect to the rubbingdirection. The full widths of the half maximum of the diffraction ofin-plane rotation, which indicate orientation distribution, weresubstantially identical to those in Example 3.

From the above results, it was confirmed that the structure of themesostructured film produced in Example 5 includes a 6-fold axisperpendicular to the film plane, indicating that the distribution of theorientation is very narrow. An incident angle of X-rays was 0.2° in thein-plane X-ray diffraction analysis. The entire sample corresponds to ananalysis region, and thus, in-plane orientation of the structure isidentical across the entire substrate. In other words, symmetricreflective surfaces of the structure each including a 6-fold axis arefacing in the same direction across the entire film.

A mesostructured silica film having a narrow distribution in in-planeorientation was observed in Example 5 when two kinds of surfactants wereused as a mixture in a molar ratio of C₁₈EO₁₀:C₁₈EO₂₀=1:3. This ratiodiffers from the ratio of the surfactants used in Example 3 whichprovided a narrow distribution in in-plane orientation. The mixing ratioof the surfactant having a small hydrophilic group and the surfactanthaving a large hydrophilic group used in Example 3 wasC₁₆EO₁₀:C₁₆EO₂₀=2:1. The result indicated that the mixing ratio of thesurfactants must be optimized by hydrophobic groups.

The mesostructured silica film produced in Example 5 was then calcinedunder the same conditions as in Examples 3 and 4 to remove thesurfactant, thereby forming a mesoporous silica film.

The calcined film was analyzed by X-ray diffraction, and the resultindicated that a structural period was shortened only in a thicknessdirection.

The film produced in Example 5 upon X-ray analysis exhibited similarbehavior to the film in Example 1, and thus, the film can be applied tothe optical device described in Example 1.

EXAMPLE 6

Example 6 is an example of production of: a mesostructured silica andmesoporous silica thin film having a three-dimensional structure within-plane orientation highly controlled across the entire substrate usinga substrate having a polyimide film formed thereon and subjected torubbing treatment as in Example 1, through dip-coating; and an opticalmaterial thin film in soft X-ray region.

A polyimide A film was formed on a silica glass substrate in the samemanner as in Example 1, and the substrate was subjected to rubbingtreatment under the same conditions as in Example 1.

A mesostructured silica thin film was formed on the substrate. Thesurfactant used in Example 5 contained polyethylene oxide 10 hexadecylether (C₁₆H₃₃(OCH₂CH₂)₁₀OH, abbreviated as C₁₆EO₁₀ below)

0.55 g of C₁₆EO₂₀ was dissolved in 10 ml of ethanol (EtOH), and 2.08 gof tetraethoxysilane (TEOS) was added thereto. After sufficient stirringof the mixture, 0.40 g of 0.1 M hydrochloric acid and 0.5 ml of purewater were further added to the solution, and was stirred for 2 hours,thereby preparing a solution. The final molar ratio of respectivecomponents in the solution was TEOS:EtOH:H₂O:HCl:C₁₆EO₁₀=1:22:5:0.004:0.08.

The solution was applied through dip-coating onto the substrate havingpolyimide A formed thereon and subjected to rubbing treatment and wasdried. A step of exposing the substrate to a steam atmosphere may beadded. A continuous film of a mesostructured silica was formed on thesubstrate. The thickness of the mesostructured silica thin film wasdetermined using a stylus profilometer, and was about 500 nm.

The film was analyzed by θ-2θ scanning X-ray diffraction with CuKαradiation, and diffraction peaks were observed at 1.20° and 2.50°.

The structure of the thin film was more specifically analyzed throughin-plane X-ray diffraction with CuKα radiation. A diffraction peak wasobserved at 2θ_(X)=1.31° through in-plane X-ray diffraction analysis. Asin Example 1, the intensity of the diffraction peak was small withmeasurement in such an initial arrangement that the substrate planeprojection component of the incident X-rays was parallel with therubbing direction. The intensity was large with measurement in such aninitial arrangement that the substrate plane projection component of theincident X-rays was perpendicular to the rubbing direction, therebyconfirming strong in-plane anisotropy in orientation of the latticeplane in the film produced in Example 6.

Next, a detector was fixed at a position of 2θ_(X)=1.31° in the in-planeX-ray diffraction analysis, and the sample was subjected to in-planerotation, investigating the orientation of the plane. As a result, sharpdiffraction peaks were observed every 60° at equal intervals as inExample 1. The positions of the diffraction peaks were in directions of+150°, +90°, +30°, −30°, −90°, and −150° with respect to the rubbingdirection.

From the above results, it was confirmed that the mesostructured thinfilm produced in Example 5 has a structure with a 6-fold axisperpendicular to the film plane, and that the distribution of theorientation is very narrow. Incident angle of X-rays was 0.2° in thein-plane X-ray diffraction analysis. The entire sample corresponds to ananalysis region, and thus, in-plane orientation of the structure isidentical across the entire substrate. In other words, symmetricreflective surfaces of the structure each including a 6-fold axis arefacing in the same direction across the entire film.

The mesostructured silica produced in Example 5 was then calcined underthe same conditions as those in. Example 1 to remove the surfactant,thereby forming a mesoporous silica thin film.

The calcined thin film was similarly analyzed by X-ray diffraction, andthe result indicated that a structural period was shortened only in athickness direction.

The thin film produced in Example 5 upon X-ray analysis exhibitedsimilar behaviors to the thin film in Example 1, and thus, the film canbe applied to an optical device described in Example 1.

EXAMPLE 7

Example 7 is an example of production of: a mesostructured silica andmesoporous silica thin film having a three-dimensional structure within-plane orientation highly controlled across the entire substrate usinga substrate having a polyimide film formed thereon and subjected torubbing treatment as in Example 1, through spin-coating; and an opticalmaterial thin film in soft X-ray region.

A polyimide A film was formed on a silica glass substrate in the samemanner as in Example 1, and the substrate was subjected to rubbingtreatment under the same conditions as in Example 1.

A mesostructured silica thin film was formed on the substrate. Asurfactant used in Example 7 was a mixture of two kinds of surfactantsrespectively having hydrophilic polyethylene oxide portions different insize and having identical hydrophobic alkyl chains. The surfactant usedin Example 7 contained polyethylene oxide 20 hexadecyl ether(C₁₆H₃₃(OCH₂CH₂)₂₀OH, abbreviated as C₁₆EO₂₀ below) and polyethyleneoxide 10 hexadecyl ether (C₁₆H₃₃(OCH₂CH₂)₁₀OH, abbreviated as C₁₆EO₁₀below) mixed in a molar ratio of C₁₆EO₁₀:C₁₆EO₂₀=2:1.

0.32 g of C₁₆EO₁₀ and 0.26 g of C₁₆EO₂₀ were dissolved in 10 ml ofethanol (EtOH), and 2.08 g of tetraethoxysilane (TEOS) was addedthereto. After sufficient stirring of the mixture, 0.40 g of 0.1 Mhydrochloric acid and 0.5 ml of pure water were further added to thesolution, and was stirred for 2 hours, thereby preparing the solution.The final molar ratio of respective components in the solution wasTEOS:EtOH:H₂O:HCl:C₁₆EO₁₀:C₁₆EO₂₀=1:22:5:0.004:0.047:0.023.

The solution was applied through spin-coating onto the substrate havingpolyimide A formed thereon and subjected to rubbing treatment and wasdried. Spin-coating was carried out at 2,000 rpm for 20 sec, for filmformation. A continuous film of a mesostructured silica was formed. Athickness of the mesostructured silica thin film was determined using astylus profilometer, and-was about 400 nm.

The film was analyzed by θ-2θ scanning X-ray diffraction with CuKαradiation, and diffraction peaks corresponding to plane interval of 5.4nm and 2.7 ram were observed at 1.66° and 3.25°, respectively.Anisotropy in the diffraction patterns as in Example 3 was observedbetween a case where the measurement was carried out in the direction ofa substrate plane projection component of incident X-rays parallel withthe rubbing direction and a case where the measurement was carried outin the direction of a substrate plane projection component of incidentX-rays perpendicular to the rubbing direction.

The structure of the thin film was more specifically analyzed throughin-plane X-ray diffraction. Two diffraction peaks were observed at2θ_(X)=1.19° and 2.37° as in Example 3. As in Example 3, the intensitiesof the diffraction peaks were small with measurement in such an initialarrangement that the substrate plane projection component of theincident X-rays was parallel with the rubbing direction. The intensitieswere large with measurement in such an initial arrangement that thesubstrate plane projection component of the incident X-rays wasperpendicular to the rubbing direction, thereby confirming strongin-plane anisotropy in orientation of the lattice plane of the filmproduced in Example 7.

Next, a detector was fixed at a position of 2θ_(X)=1.19° in the in-planeX-ray diffraction analysis, and the sample was subjected to in-planerotation, investigating the orientation of the plane. As a result, sharpdiffraction peaks were observed every 60° at equal intervals as inExample 3. The positions of the diffraction peaks were in directions of+150°, +90°, +30°, −30°, −90°, and −150° with respect to the rubbingdirection.

From the above results, it was confirmed that the mesostructured thinfilm produced in Example 7 has a structure with a 6-fold axisperpendicular to the film plane, and that the distribution of theorientation is very narrow. An incident angle of X-rays was 0.2° in thein-plane X-ray diffraction analysis. The entire sample corresponds to ananalysis region, and thus, in-plane orientation of the structure isidentical across the entire substrate. In other words, symmetricreflective surfaces of the structure each including a 6-fold axis arefacing in the same direction across the entire film.

The mesostructured silica produced in Example 7 was then calcined underthe same conditions as those in Example 1 to remove the surfactant,thereby forming a mesoporous silica thin film.

The calcined film was analyzed by X-ray diffraction, and the resultindicated that a structural period was shortened only in a thicknessdirection.

The thin film produced in Example 7 upon X-ray analysis exhibitedsimilar behaviors to the thin film in Example 1, and thus, the film canbe applied to the optical device described in Example 1.

EXAMPLE 8

Example 8 is an example of production of: a mesostructured silica andmesoporous silica thin film each having a three-dimensional structurewith in-plane orientation highly controlled across the entire substrateusing a substrate having a polyimide film formed thereon and subjectedto rubbing treatment as in Example 1, on an optional position of thesubstrate by soft lithography through dip-coating; and an opticalmaterial thin film in soft X-ray region.

A polyimide A film was formed on a silica glass substrate in the samemanner as in Example 1, and the substrate was subjected to rubbingtreatment under the same conditions as in Example 1.

A mesostructured silica thin film was formed on the substrate. Asurfactant used in Example 8 was a mixture of two kinds of surfactantsrespectively having hydrophilic polyethylene oxide portions different insize and having identical hydrophobic alkyl chains. The surfactant usedin Example 8 contained polyethylene oxide 20 hexadecyl ether(C₁₆H₃₃(OCH₂CH₂)₂₀OH, abbreviated as C₁₆EO₂₀ below) and polyethyleneoxide 10 hexadecyl ether (C₁₆H₃₃(OCH₂CH₂)₁₀OH, abbreviated as C₁₆EO₁₀below) mixed in a molar ratio of C₁₆EO₁₀:C₁₆EO₂₀=2:1.

0.32 g of C₁₆EO₁₀ and 0.26 g of C₁₆EO₂₀ were dissolved in 10 ml ofethanol (EtOH), and 2.08 g of tetraethoxysilane (TEOS) was addedthereto. After sufficient stirring of the mixture, 0.40 g of 0.1 Mhydrochloric acid and 0.5 ml of pure water were further added to thesolution, and was stirred for 2 hours, thereby preparing the solution.The final molar ratio of respective components in the solution wasTEOS:EtOH:H₂O:HCl:C₁₆EO₁₀:C₁₆EO₂₀=1:22:5:0.004:0.047:0.023.

A micromold, which is made from polydimethylsiloxane, was pressed onto asubstrate having polyimide A formed thereon and subjected to rubbingtreatment. A precursor solution was introduced into the mold by pouringthe precursor solution from an edge of the mold and using capillarity,and was left standing for 5 hours, and then the mold was removed fromthe substrate, thereby obtaining a patterned mesostructured thin film.Upon observing the substrate having been dried in air, it was confirmedthat a transparent thin film was formed only on the region coated withthe precursor solution through soft lithography.

The film was analyzed by θ-2θ scanning X-ray diffraction with CuKαradiation, and diffraction peaks corresponding to plane interval of 5.4nm and 2.7 nm were observed at 1.67° and 3.25°, respectively. Anisotropyin the diffraction patterns as in Example 3 was observed between a casewhere the measurement was carried out in the direction of a substrateplane projection component of incident X-rays parallel with the rubbingdirection and a case where the measurement was carried out in thedirection of a substrate plane projection component of incident X-raysperpendicular to the rubbing direction.

The structure of the thin film was more specifically analyzed throughin-plane X-ray diffraction. Two diffraction peaks were observed at2θ_(X)=1.18° and 2.37° as in Example 3. As in Example 3, the intensitiesof the diffraction peaks were small with measurement in such an initialarrangement that the substrate plane projection component of theincident X-rays was parallel with the rubbing direction. The intensitieswere large with measurement in such an initial arrangement that thesubstrate plane projection component of the incident X-rays wasperpendicular to the rubbing direction, thereby confirming strongin-plane anisotropy in orientation of the lattice plane in the filmproduced in Example 8.

Next, a detector was fixed at a position of 2θ_(X)=1.18° in the in-planeX-ray diffraction analysis, and the sample was subjected to in-planerotation, investigating the orientation of the plane. As a result, sharpdiffraction peaks were observed every 60° at equal intervals as inExample 3. The positions of the diffraction peaks were in directions of+150°, +90°, +30°, −30°, −90°, and −150° with respect to the rubbingdirection.

From the above results, it was confirmed that the mesostructured thinfilm produced in Example 8 has a structure with a 6-fold axisperpendicular to the film plane, and that the distribution of theorientation is very narrow. Incident angle of X,-rays was 0.2° in thein-plane X-ray diffraction analysis. The entire sample corresponds to ananalysis region, and thus, in-plane orientation of the structure isidentical across the entire substrate. In other words, symmetricreflective surfaces of the structure including a 6-fold axis are facingin the same direction across the entire film.

The mesostructured silica produced in Example 8 was then calcined underthe same conditions as those in Example 1 to remove the surfactant,thereby forming a mesoporous silica thin film.

The calcined thin film was similarly analyzed by X-ray diffraction, andthe result indicated that a structural period was shortened only in athickness direction.

The thin film produced in Example 8 upon X-ray analysis exhibitedsimilar behavior to the thin film in Example 1, and thus, the film canbe applied to an optical device described in Example 1.

EXAMPLE 9

Example 9 is an example of production of: a mesostructured silica andmesoporous silica thin film having a three-dimensional structure within-plane orientation highly controlled across the entire substrate usinga substrate having a polyimide film formed thereon and subjected torubbing treatment as in Example 1, on an optional position of thesubstrate through pen lithography; and an optical material thin film insoft X-ray region.

A polyimide A film was formed on a silica glass substrate in the samemanner as in Example 1, and the substrate was subjected to rubbingtreatment under the same conditions as in Example 1.

A mesostructured silica thin film was formed on the substrate. Asurfactant used in Example 9 was a mixture of two kinds of surfactantsrespectively having hydrophilic polyethylene oxide portions different insize and having identical hydrophobic alkyl chains. The surfactant usedin Example 9 contained polyethylene oxide 20 hexadecyl ether(C₁₆H₃₃(OCH₂CH₂)₂₀OH, abbreviated as C₁₆EO₂₀ below) and polyethyleneoxide 10 hexadecyl ether (C₁₆H₃₃(OCH₂CH₂)₁₀OH, abbreviated as C₁₆EO₁₀below) mixed in a molar ratio of C₁₆EO₁₀:C₁₆EO₂₀=2:1.

0.32 g of C₁₆EO₁₀ and 0.26 g of C₁₆EO₂₀ were dissolved in 10 ml ofethanol (EtOH), and 2.08 g of tetraethoxysilane (TEOS) was addedthereto. After sufficient stirring of the mixture, 0.40 g of 0.1 Mhydrochloric acid and 0.5 ml of pure water were further added to thesolution, and was stirred for 2 hours, to thereby prepare the solution.The final molar ratio of respective components in the solution wasTEOS:EtOH:H₂O:HCl:C₁₆EO₁₀:C₁₆EO₂₀=1:22:5:0.004:0.047:0.023.

The solution was patterned on the substrate having polyimide A formedthereon and subjected to rubbing treatment through pen lithography as inFIG. 12, and was dried in air at room temperature. Conditions for penlithography include a pen orifice of 50.0 μm, a substrate movement rateof 2.5 cm/s, and a fluid supply rate of 4.0 cm.

Upon observing the substrate having been dried in air, it was confirmedthat a transparent thin film was formed only on the region coated withthe solution through pen lithography.

The film was analyzed by θ-2θ scanning X-ray diffraction with CuKαradiation, and diffraction peaks corresponding to plane interval of 5.4nm and 2.7 nm were observed at 1.66° and 3.24°, respectively. Anisotropyin the diffraction patterns as in Example 3 was observed between a casewhere the measurement was carried out in the direction of a substrateplane projection component of incident X-rays parallel with the rubbingdirection and a case where the measurement was carried out in thedirection of a substrate plane projection component of incident X-raysperpendicular to the rubbing direction.

The structure of the thin film was more specifically analyzed throughin-plane X-ray diffraction. Two diffraction peaks were observed at2θ_(X)=1.18° and 2.36° as in Example 3. As in Example 3, the intensitiesof the diffraction peaks were small with measurement in such an initialarrangement that the substrate plane projection component of theincident X-rays was parallel with the rubbing direction. The intensitieswere large with measurement in such an initial arrangement that thesubstrate plane projection component of the incident X-rays wasperpendicular to the rubbing direction, thereby confirming strongin-plane anisotropy in orientation of the lattice plane in the filmproduced in Example 9.

Next, a detector was fixed at a position of 2θ_(X)=1.18° in the in-planeX-ray diffraction analysis, and the sample was subjected to in-planerotation, to investigate the orientation of the plane. As a result,sharp diffraction peaks were observed every 60° at equal intervals as inExample 3. The positions of the diffraction peaks were in directions of+150°, +90°, +30°, −30°, −90°, and −150° with respect to the rubbingdirection.

From the above results, it was confirmed that the mesostructured thinfilm produced in Example 9 has a structure with a 6-fold axisperpendicular to the film plane, and that the distribution of theorientation is very narrow. An incident angle of X-rays was 0.2° in thein-plane X-ray diffraction analysis. The entire sample corresponds to ananalysis region, and thus, in-plane orientation is identical across theentire substrate. In other words, symmetric reflective surfaces of thestructure each including a 6-fold axis are facing in the same directionacross the entire film.

The mesostructured silica produced in Example 9 was then calcined underthe same conditions as those in Example 1 to remove the surfactant,thereby forming a mesoporous silica thin film.

The calcined thin film was similarly analyzed by X-ray diffraction, andthe result indicated that a structural period was shortened only in athickness direction.

The thin film produced in Example 9 upon X-ray analysis exhibitedsimilar behavior to the thin film in Example 1, and thus, the film canbe applied to an optical device described in Example 1.

The film according to the present invention can be applied to X-rayoptical devices.

This application claims priority from Japanese Patent Application Nos.2003-290535 filed on Aug. 8, 2003 and 2004-029350 filed on Feb. 5, 2004,which is hereby incorporated by reference herein.

1. A mesostructured film comprising amphiphilic molecular assemblies anda compound containing as a main component silica formed on theperipheries of the molecular assemblies regularly arrangedthree-dimensionally, the mesostructured film being formed on asubstrate, wherein: a local periodic structure in a section in parallelwith the substrate of the film has a 6-fold axis perpendicular to a filmplane; and symmetric reflective surfaces of the structure including the6-fold axis are facing in the same direction across the entire film. 2.A mesostructured film according to claim 1, wherein the amphiphilicmolecular assemblies comprise surfactant micelles containing two or morenonionic surfactants of different molecular length.
 3. A mesostructuredfilm according to claim 2, wherein the two or more nonionic surfactantsof different molecular length comprise nonionic surfactants containingpolyethylene oxide as a hydrophilic group.
 4. A mesostructured filmaccording to claim 3, wherein the two or more nonionic surfactants ofdifferent molecular length respectively have identical hydrophobicportions and hydrophilic polyethylene oxide portions different inmolecular chain length.
 5. X-ray optical device comprising themesostructured film according to claim
 1. 6. mesostructured filmaccording to claim 1 having mesopores which are spherical.
 7. Amesoporous material film comprising holes regularly arrangedthree-dimensionally and silica as a main component, the mesoporousmaterial film being formed on a substrate, wherein: a local periodicstructure in a section of the film in parallel with the substrate has a6-fold axis perpendicular to a film plane; and symmetric reflectivesurfaces of the structure including the 6-fold axis are facing in thesame direction across the entire film.
 8. A mesoporous material filmaccording to claim 7, wherein the holes are spherical mesopores.
 9. Astructure comprising spherical assemblies of amphiphilic molecules and acompound containing silica formed on the peripheries of the assemblies,wherein: the amphiphilic molecular assemblies are regularly arrangedacross an entire area of the structure; and the arrangement of theamphiphilic molecular assemblies has a 6-fold axis.
 10. A structureaccording to claim 9, wherein the spherical assemblies are sphericalmesopores.
 11. A mesostructured film comprising: amphiphilic molecularassemblies arranged three-dimensionally in the mesostructured film on asubstrate, wherein a local structure of the film has a 6-fold symmetryaxis perpendicular to the film plane, and planes of mirror symmetrycontaining the symmetry axis are substantially parallel throughout thefilm.
 12. A mesostructured film according to claim 11, wherein theamphiphilic molecular assemblies are spherical mesopores.
 13. Amesostructured film having mesopores, wherein a local structure of thefilm has a 6-fold symmetry axis perpendicular to the film plane, andplanes of mirror symmetry containing the symmetry axis are parallelthroughout the film.
 14. A mesostructured film according to claim 13,wherein the mesopores are spherical.